Summary The purpose of this proposal is to test feasibility and expedite implementation of a multi-center clinical trial of weight-loss in obese patients with poorly controlled asthma within the American Lung Association's Airways Clinical Research Centers network (ALA-ACRC). Obesity is a risk factor for the development of asthma; these patients tend to have poorly controlled asthma and do not respond as well to conventional therapy. Obesity disproportionately affects minority and lower socioeconomic status populations in the United States. Single center studies suggest that weight loss might improve asthma control, but there have been no large multi-center clinical trials addressing the efficacy of weight loss in asthma. Our ultimate purpose is to test the hypothesis that weight loss, through an intensive life style intervention, will improve asthma control. However, we first need to ensure that we can institute a successful weight loss intervention in patients with asthma. We will determine the feasibility of recruiting obese patients with poorly controlled asthma from the17 clinical centers of the ALA-ACRC network by identifying 90 subjects with BMI ? 30 kg/m2 and poorly controlled asthma. At the same time we will perform a pilot study of an internet-based weight loss intervention in two ethnically and geographically distinct centers to determine efficacy of our proposed intervention in producing weight loss in patients with asthma. The results of this proposal will lay the groundwork for a definitive multicenter clinical trial of a weight loss intervention for the treatment of poorly controlled asthma in obese patients. If ultimately successful, this intervention could readily be disseminated as a remote intervention from a centralized location. This would provide an important therapy for the treatment of obese patients with asthma, a population refractory to other treatments.